Ever wondered what investors like Warren Buffett, Bill Ackman, Chuck Akre, Michael Burry and other superinvestors are really buying?
Every quarter, a rare window opens into their portfolios, giving everyday investors a chance to see how the world’s best deploy billions.
The disclosure comes in the form of a regulatory filing called a 13F, and while it isn’t perfect, it opens an intriguing window into how legendary investors and big hedge funds manage their portfolios.
What is a 13F?
A 13F is a quarterly report that US-based investment managers must file with the Securities and Exchange Commission (SEC) if they oversee more than US$100 million in assets. The requirement applies to hedge funds, mutual funds, pension funds and some family offices, meaning thousands of professional investors publish snapshots of their US-listed holdings four times a year.
The key word is snapshot. A 13F simply lists the long positions in US-listed equities and a few other securities at the end of the quarter. It doesn’t necessarily include short positions, options exposure, cash allocations, or foreign-listed investments. Nor does it reveal the portfolio manager’s rationale. It is a factual record, nothing more.
The limitations investors often overlook
Because 13Fs show positions as they were, not as they are today, they are inherently backward looking. Managers have 45 days after the end of each quarter to submit their filings. A position you see today may have already been trimmed, closed, or doubled.
Another important limitation is visibility. A global conglomerate such as Berkshire Hathaway (NYSE:BRK.A NYSE:BRK.B) owns dozens of private businesses and listed companies outside the US, none of which appear in a 13F. The document only reveals one slice of the story.
For example, Berkshire’s ownership of See’s Candies, BNSF Rail or Dairy Queen doesn’t appear in the filing, even though these are some of Buffett’s most important long-term investments. The same applies to holdings in international markets. Li Lu at Himilaya Capital (known for the only fund manager trusted by Charlie Munger outside of Buffett), for instance, may hold major Asian equities that never appear in a US 13F.
So investors should treat 13Fs as informative, not complete.
Still, they’re a treasure trove for idea generation
Despite the drawbacks, 13Fs remain one of the most interesting datasets available to individual investors. Sites such as Dataroma and WhaleWisdom make the information easy to explore. They compile filings, track changes in positions over time, and provide helpful visualisations — like the “most owned stocks,” “big bets,” and “top buys last quarter” tables shown in the screenshot.
These platforms let you compare the behaviour of some of the world’s best investors side by side. That comparison alone can be educational.
Take Alphabet (NASDAQ:GOOGL) as an example. Last quarter, Berkshire Hathaway initiated a position — a rare step into big tech. At the same time, investors like Bill Ackman and Terry Smith reduced their allocations. The divergence highlights a deeper truth: even elite investors differ in their views, time horizons and valuation frameworks.
This is where the fun begins. Used well, 13Fs can help you generate ideas and you can observe patterns, study conviction levels, and see how investors concentrate or diversify their portfolios.
A helpful tool, not a roadmap
It is tempting to treat 13Fs as a shortcut — simply copy the moves of great investors. The problem is that you are only seeing a partial, delayed picture. You do not see private businesses, foreign assets, hedges, cash balances, or the reasoning behind each decision.
You also do not know whether a position was initiated by the lead investor or a deputy.
The strongest use of 13Fs is educational: they help investors think more broadly, expose them to new businesses, and offer a window into professional decision-making.
For long-term investors, that’s where the real value lies… not in imitation, but in inspiration.
